I actually do have quick detailer in my trunk. [:I]
I'm not sure I'd be brave enough to use Bar Keeper's Friend on my windshield (even though my windshield is in pretty crappy condition) because it is in fact, an abrasive. OTOH, I have used 0000 steel wool on my garage windows to remove 7 decades of built-up film and crud. It worked well but on the areas where I scrubbed a little too hard or didn't have enough water, there are scratches.
Agree that it is much easier to clean the bugs off while they are still fresh, using quick detailer and a micro fiber towel.
Oh forgot to mention, BKF worked great for getting rid of rust stains in my bathtub when, like a moron, I used a bleach-based cleaner on a cast iron tub that's been refinished. It's a good product and has lots of uses, but I would make sure to have lots of water and test in a small place first before using it on glass.
